The following may aid someone with a Wonder Dog.

Begin with a fence. The other side has sandpaper as a non-slip. ...




Note that the face of the Wonder Dog has leather glued on. This cushions and also acts as a non-slip.




Place the fence in the vise (leg vise in my case) ...



... but do not close it up tight. Leave about 3mm free ...



Now place the stretcher-to-be-morticed between the Wonder Dog and the fence, tighten the Wonder Dog, then clamp down tighter with the main vise/fence ...



There is not enough clamping pressure from the Wonder Dog alone. The vise will exert the extra that is needed.

The stretcher is not going anywhere!



Regards from Perth

Derek